1. Field of the Invention
The present invention relates to a reagent injection apparatus for injecting specified reagents into lesions and other locations in body tissues, as well as a production method of reagent injection apparatus thereof.
2. Description of the Related Art
Traditionally, various treatments, inspections, procedures and other medical manipulations have been conducted by inserting medial apparatuses, such as catheters, into blood vessels, gastrointestinal tract, urinal tract, and various other tubular organs and tissues in the patient's body. In recent years, treatments and other procedures are also carried out wherein reagent injection apparatuses such as reagent injection catheters are used to inject specified reagents into lesions in body tissues (Japanese Patent Laid-open No. 2001-299927 for an example).
These reagent injection apparatuses used in treatments and other procedures performed by means of reagent injection into lesions have a structure whereby a needlelike tubular body is inserted into a main tube in a manner movable in the axial direction. Also, such needlelike tubular body has an interior hole through which specified reagent can flow. With reagent injection apparatuses having this structure, the tip (needle) of the needlelike tubular body projects from the main tube that has been inserted into the blood vessels, in order to puncture the target lesion in body tissue and thereby inject specified reagent into the lesion through the interior hole in the needlelike tubular body.
For example, reagent injection apparatuses having the above structure include those equipped with two guide wires to smoothly puncture the target lesion in body tissue using the needle (Japanese Patent Laid-open No. 2004-267333 for an example).
Specifically, reagent injection apparatuses of such structure have one guide wire extending outward from the tip of the main tube, and another guide wire extending outward from the side face of the main tube. When the main tube has been inserted into one of two specified branching blood vessels, the guide wire extending out of the tip of the main tube is inserted into the branching blood vessel. On the other hand, the guide wire extending out of the side face of the main tube is inserted into the other branching blood vessel. In this condition, the needle is projected out of the main tube to puncture the target lesion in body tissue.
Such a reagent injection apparatus having two guide wires allow the two guide wires respectively inserted into the two branching blood vessels to receive the reactive force acting upon the needle, which generates when the needle punctures the body tissue. As a result, the needle can more reliably and smoothly puncture the body tissue to a desired depth compared to when a reagent injection apparatus equipped with only one guide wire is used.
In the use of these conventional reagent injection apparatuses, however, it is difficult, simply by inserting the two guide wires into the two branching blood vessels, to sufficiently suppress movement or rotation of the main tube around the axis caused by the reactive force generated when the needle punctures the body tissue or by any other acting force resulting from twisting or other movement of the needle. For the reason, in some cases sufficient effect cannot be obtained to operate the needle to smoothly puncture a specified position in body tissue to a desired depth, particularly in situations where the main tube must be stably positioned in the blood vessel to perform puncture operation, such as when puncturing the cardiac muscle or other relatively hard lesions with the needle. As a result, the aforementioned traditional apparatuses are used with a balloon provided on the main tube, and this balloon is inflated to ensure stable positioning inside the blood vessel.